Winding a strong electromagnet

[Kator01]

Hi capthook,

thank you very much. Now I have saved a copy. Great find.

Regards

Kator01

[capthook]

A 2nd Ebook of interest is:

Solenoids, Electromagnets & electromagnetic windings
423 pages, 7MB

A good complement to the first and written 25 later.
The author, Underhill, writes this in reference to the author of the 1st ebook link:

"The labors of Professor Silvanus P. Thompson in this field deserve recognition from the electrical profession, to which the author desires to add his personal acknowledgments."

The file is here:

http://www.filepanda.com/file/2rpkksms11kj/

[capthook]

1st attach picture:

A graph showing the results of different core materials using a small test coil as a generator coil.


2nd pic: MIG welding wire

Ran across this interesting core idea:

"Get yourself a roll of .030 MIG welding wire.

Make your coil form so that there is very little airspace at the center of the winding.

Wind the steel wire in tandem with the copper wire on the same form.

What you have there is an integrated, ultra-low eddy-current ferrous core.

You can also do this with regular mechanics wire. But, it's usually kinda dirty and oily right on the roll. MIG wire is nice and shiny."

What you lose in winding space for the copper wire because of the steel wire might be similiar to what you gain in being able to wind the coil to a smaller inner dimension?
Either way - an interesting idea I've never heard of!

[Xaverius]

1st attach picture:

A graph showing the results of different core materials using a small test coil as a generator coil.


2nd pic: MIG welding wire

Ran across this interesting core idea:

"Get yourself a roll of .030 MIG welding wire.

Make your coil form so that there is very little airspace at the center of the winding.

Wind the steel wire in tandem with the copper wire on the same form.

What you have there is an integrated, ultra-low eddy-current ferrous core.

You can also do this with regular mechanics wire. But, it's usually kinda dirty and oily right on the roll. MIG wire is nice and shiny."

What you lose in winding space for the copper wire because of the steel wire might be similiar to what you gain in being able to wind the coil to a smaller inner dimension?
Either way - an interesting idea I've never heard of!

Nice suggestion, any idea of the permeabilty of welding wire?  Btw, how is your electrical steel/ferrite projects progressing?  I received a 6" long/1" diameter ferrite rod from Stormwise.com.  It was encased in 1/8th thick plastic tubing for weatherproofing.  I chiseled off the plastic today and found two 3" segments pushed together end to end.  I wound one segment with 80' of 26 gauge wire.  When I went to test it, I found that my 9 volt battery was dead!  #%!&^$...very frustrating.  I'll have to get a battery and test it Saturday, will post the results then.

[capthook]

The welding wire idea was just a new/odd idea I thought I'd share - thinking it's probably not a real solution.

Glad you got your ferrite - looking forward to your results! Odd it is 2 pieces - hopefully they are even a better size now to work with.

I ordered mine from where I did because I didn't want that plastic tubing, wanted different sizes, was cheaper, and quicker delivery.  It should be here tommorrow 

What are your winding dimensions?
How are you going to test?  1 or 2 "D" batteries (1.5v or 3v) may be easier for testing than 9v?

The "strength" tests I've done are holding strength - as in a traction style EM.  It should be relative to an airgap EM.  They have been geared towards wire size, winding depth and length, and power consumption. 
Using a 5/16" hex bolt as weight and adding nuts and washers to add/subtract to that weight to determine the holding power.  Then weighing it to determine ounces/lbs of pull.
It could also be expressed as: 5/16" x 4" hex bolt with 5 nuts and 3 washers.

Is this a testing method you will pursue?  What other options/methods have you considered?
Anyone else with comments?

The earlier tests were add hock - and I didn't take adequte notes.

Once I get the ferrite - I will perform the above method with various cores and windings and post results.